Digital Commons Network^™

24-H Circadian Rest-Activity Rhythms And Physical Frailty In Older Adults: A Biopsychosocial Perspective On Sex Differences And Social Capital, Jisu Kim

Theses and Dissertations

Physical frailty is a prevalent geriatric syndrome characterized by age-related decline across multiple physiological systems. Physical frailty is associated with an elevated risk of adverse health outcomes, including chronic disease progression and all-cause mortality, representing a significant and growing public health concern. Disrupted circadian rest-activity rhythms (RARs) are increasingly recognized as clinically meaningful markers of physical frailty in older adults. However, the extent to which biological sex and social determinants of health (SDoH), particularly social capital, contribute to or modify the associations between RARs and physical frailty remains underexplored.

Therefore, this dissertation summarizes the existing literature on age-related changes in …

A Mathematical Frameworks For Singular, Nonlinear Phenomena: Applications To Nematocyst Firing And Inhomogeneous Nls With Coulomb Potential, Abdulrahman Alharbi

Theses and Dissertations

Nematocysts are specialized cellular organelles found in all cnidarians, including corals and jellyfish, as well as in some single-celled protists such as dinoflagellates. These organelles display remarkable diversity in morphology and function, playing roles in prey capture and defense. The firing of a nematocyst is one of the fastest accelerations in nature, yet the underlying physical mechanisms remain not fully understood. In this work, we address key questions: how sufficient force is generated to overcome the fluid boundary layer, whether fluid–structure interaction models can reproduce observed dynamics, and what mechanisms trigger discharge.

Our research investigates models based on osmotic pressure …

Internalizing Symptoms In Lgbtq+ Young Adults: Understanding The Roles Of Social Support And Resilience To Social Stigma, Chloe M. Sobolewski

Theses and Dissertations

LGBTQ+ young adults are at increased risk of adverse mental health outcomes including internalizing symptoms. The current study seeks to better incorporate strengths when modeling internalizing symptoms outcomes in LGBTQ+ young adults. The present study is secondary analysis of data collected as part of a three-wave longitudinal study. LGBTQ+ young adults (N = 250) completed baseline questionnaires assessing resilience to social stigma, types of perceived social support (i.e., family, friend, significant other), and internalizing symptoms. Moderation models were not practically or statistically significant; however, covariates (i.e., age, socioeconomic standing, and childhood basic needs) stood out in their significant contribution in …

Examining Youth Ethnic Identity And Parental Familismo As Protective Factors Against Bicultural Stress And Internalizing Symptoms In Latino Youth, Daniella Olivares

Theses and Dissertations

Adolescence is a critical developmental period marked by increased vulnerability to mental health challenges. For Latino adolescents living in the U.S., experiences of bicultural stress may heighten the risk for adverse mental health outcomes. However, cultural strengths–such as youth ethnic identity and parental familismo–may serve as protective factors. The current study examined whether youth ethnic identity and parental familismo moderated the relationship between bicultural stress and internalizing symptoms among a diverse sample of Latino youth in central Virginia. Latino adolescents (n = 60) completed measures assessing bicultural stress, ethnic identity, and internalizing symptoms, while parents (n = 60) reported on …

Synthesis Of Iso-Dityrosine, A Potential Biomarker Of Neurodegenerative Diseases, Brandon R. Knouse

Theses and Dissertations

As the population of the United States continues to age, the prevalence of neurodegenerative disorders is rising, increasing the societal and clinical burden of diseases such as Parkinson’s disease and dementia-related conditions. Lewy Body Dementia (LBD), the second most common cause of dementia, shares underlying neuropathological features with Parkinson’s disease, including the aggregation of misfolded α-synuclein into Lewy bodies and Lewy neurites. Current diagnostic approaches rely heavily on cerebrospinal fluid biomarker analysis; however, significant overlap exists among biomarkers associated with Alzheimer’s disease and other neurodegenerative conditions, limiting diagnostic specificity. Emerging evidence suggests that oxidative modifications of α-synuclein, particularly the formation …

Tuberculosis In Jim Crow Virginia, 1900-1972, Elizabeth Dooley

Theses and Dissertations

Tuberculosis (TB) was a major public health concern in the United States, especially in the first half of the twentieth century. Transmission and treatment of the disease, which is spread between humans through close contact, was complicated by racial segregation laws in the South known as Jim Crow laws. Virginia subscribed to these laws, which played a role in how and where Black Virginians with TB could be treated. Segregated treatment facilities with an inadequate number of beds for the number of infected people and deaths in the state added to these complications of disease control and plan for eradication. …

Early Math Readiness And Later Achievement: A Longitudinal Study, Bailey Bontrager

Theses and Dissertations

The current body of literature provides much evidence that mathematics skills at the start of kindergarten are predictive of later mathematics achievement, and that students enrolled in early childhood education (ECE) programs are better prepared for mathematics at the start of kindergarten. However, the potential for children to develop mathematical skills prior to entering kindergarten relies on access to ECE programs and resources in families’ surrounding communities. Recent use of geospatial data collection techniques and measures of community resource availability have enabled researchers to examine specific localities for the ways in which community organizations and institutions support residents in particular …

Comparison Of Artificial Intelligence Vs Human Observer For Periapical Radiolucency Detection, Adam J. Pink

Theses and Dissertations

Objective: The aim of this study was to assess the performance of an Artificial Intelligence (AI) program (OverJet AI) with that of experienced endodontic residents, endodontists, a radiologist, and dental students in detecting periapical radiolucencies using radiographic images.

Methods: One hundred and fifty periapical radiographic images were analyzed using the OverJet AI software to determine the presence/absence of a periapical radiolucency as well as the size (small 1-3mm, medium 4-6mm, and large 6+mm). The unaltered images were also evaluated by two endodontic residents, two practicing endodontists, an oral radiologist and two 4th year dental students.

Results: Agreement between the AI …

Nanomagnet Based Reservoir Computing And Quantum Control, Fahim F. Chowdhury

Theses and Dissertations

Conventional CMOS scaling has driven remarkable advances in computing but faces increasing physical and energy constraints, motivating alternative computing paradigms that integrate memory and computation while improving energy efficiency. Nanoscale magnetic systems offer a promising platform for such approaches because their intrinsic nonlinear dynamics and localized magnetic fields can support both classical and quantum information processing. This thesis investigates nanomagnetic systems for physical reservoir computing and, with primary emphasis, for localized quantum control of spin qubits.

The first part explores dipole-coupled nanomagnet arrays as physical reservoirs. Micromagnetic simulations demonstrate nonlinear dynamical behavior with high short-term memory and parity-check capacity, enabling …

Integration Of Whole Genome Sequence And Rna-Sequencing Data For Disease-Specific Phenotype Prediction, Leiliani M. Clark

Theses and Dissertations

Breast cancer is a heterogeneous disease driven by complex genomic and transcriptomic alterations, making accurate phenotype prediction a challenging task. Recent advances in genomic foundation models and representation learning provide new opportunities to extract biologically meaningful features directly from sequencing data. The objective of this study was to develop and evaluate a multimodal framework integrating whole genome sequence (WGS) and RNA sequencing (RNA-Seq) embeddings for breast cancer classification. DNABERT-2, a DNA foundation model, was evaluated for its ability to generate genomic representations from The Cancer Genome Atlas breast cancer (TCGA-BRCA) WGS data, and the impact of downstream fine-tuning on embedding …

Local Lung Delivery Of Ginkgetin For Therapeutic Intervention In Lung Fibrosis, Cimone L. Richardson

Theses and Dissertations

Lung fibrosis (LF) is a progressive, irreversible pathological condition in the lungs that is ultimately fatal. Current drug treatments (nintedanib, pirfenidone, and nerandomilast) slow disease progression but cause significant systemic adverse effects due to oral administration. Transient receptor potential vanilloid 4 (TRPV4), a mechanosensitive ion channel, may play a role in LF progression and represent a novel anti-LF target. Ginkgetin (GKT), a natural biflavonoid, is a potent TRPV4 inhibitor with anti-inflammatory and antioxidative properties. Local lung delivery could achieve high local lung concentrations while minimizing systemic exposure. Accordingly, this project evaluates GKT's therapeutic intervention efficacy in LF via local lung …

Discrete Cell Signaling Differences Cause Female-Dominant Il-33 Responses In Mast Cells, Tania D. Maldonado

Theses and Dissertations

Many allergic diseases are more common and severe in women than in men. A key component of allergic inflammation is IL-33, a cytokine released by epithelial cells after allergen exposure. Because mast cells are a central early responder in allergic disease and are activated by IL-33, we investigated sex differences in mast cell responses to IL-33. We first found that male mast cells expanded poorly in standard RPMI-based culture media containing phenol red, which has estrogenic properties. Male cells also responded poorly to IL-33 when cultured with in media containing phenol red. In contrast, female mast cells expanded 3-fold less …

Climate, Biogeography, And Dispersal: A Unifying Framework For Ameri-Caribbean Dry Forests, Pablo Lopez Bustamante

Theses and Dissertations

Seed dispersal is a crucial ecological function that enables plants to alter their distributional range, avoid intense competition and natural enemies near the parent plant, and recover from disturbances. These processes shape species and functional composition of forests. Wind has traditionally been considered the dominant dispersal mechanism in Ameri-Caribbean dry forests, yet growing evidence suggests that other dispersal mechanisms also play significant roles in this ecosystem, responding differently to biotic and abiotic conditions. Still, how dispersal syndrome composition influences plant communities, the ecological drivers underlying these patterns, and the effects of climate change on dispersal syndrome dominance remain poorly understood. …

Sex In Plants: Birth, Death, And Trying To Survive In Changing Climates, Elena M. Meyer

Theses and Dissertations

Plant mating systems are key determinants of fitness. Angiosperms exhibit a wide variety of reproductive strategies, including self-fertilization (or selfing), outcrossing, and mixed mating. It has been estimated that up to 43% of plant species are capable of selfing, and selfing has been hypothesized to provide reproductive assurance where opportunities for mating may be limited, such as in marginal environments. However, questions regarding the overall distribution of selfing rates across angiosperms, the maintenance of mixed mating in the face of inbreeding depression, and the impact of self-fertilization on diversification rates remain incompletely resolved. Here, we explore the dynamics of self-fertilization …

Empirical Dynamical Modeling Of Cortico-Hippocampal Information Transfer During Memory Encoding, Sam Y. Cole

Theses and Dissertations

Understanding how brain dynamics support successful memory formation remains a central challenge in neuroscience. This dissertation applies tools from empirical dynamical systems theory to investigate the neural mechanisms underlying episodic encoding, with a focus on cortico-hippocampal interactions. Using stereoelectroencephalography (sEEG) data recorded during a delayed free recall of word lists task, this work reveals nonlinear, state-dependent shifts in directed information flow between cortex and hippocampus that distinguish successful from unsuccessful encoding. To further characterize these dynamics, state-space trajectories are reconstructed using time-delay embedding and recurrence-based methods, and features derived from these trajectories are used to classify memory outcomes. By integrating …

Machine Learning Modeling Of In-Situ Effective Thermal Conductivities And Ablation Behaviors Of Ceramic Matrix Composites Under Hydrogen Combustion Environments For Gas Turbine Engines, Jayanta Bhusan Deb

Graduate Studies Theses and Dissertations 2026

Through the integration of experimental characterization, machine learning, deep learning, numerical modeling, and physics-informed artificial intelligence, this dissertation explores the thermal performance of polymer-derived ceramic matrix composites (CMCs) for hydrogen combustion environments. The polymer infiltration and pyrolysis (PIP) process was used to create Yttria-stabilized zirconia (YSZ)-fiber-reinforced ceramic matrix composites, which were then experimentally assessed under hydrogen torch and hydrogen combustion conditions typical of next-generation gas turbine and aerospace propulsion systems. Front- and back-surface temperature measurements were used to continually monitor thermal reactions, and post-test microstructural characterization and numerical simulations were carried out to evaluate material integrity and heat-transfer behavior. To …

Assessment Of Major Adverse Cardiovascular Event Across Diverse Racial Groups Of Psoriasis Patients On Biologic Therapy: A Retrospective Cohort Study, Chunghwan Ro, Ana Ormaza Vera, Waleed Adawi, Clinton W. Enos

Department Dermatology Faculty Publications

Psoriasis is associated with an increased risk of major adverse cardiovascular events (MACE), and biologic therapy may reduce this risk by targeting systemic inflammation. However, limited data exist on whether long term MACE risk differs by biologic class or across racial groups. We conducted a retrospective cohort study to assess the risk of primary MACE in psoriasis patients receiving biological therapies, stratified by biological class, compared with biologic-naïve psoriasis patients. Whether MACE risk among biologic-treated patients varied by race was further examined. After 1:1 propensity score matching, 36 330 biologic-treated patients were compared with 36 330 non-biologic-treated patients. Incident MACE …

Implementation Of Tg-351 Reference Dosimetry For A 6 Mv Photon Beam In An Mr-Guided Radiotherapy System, Nicholas A. Castellano Jr.

Theses and Dissertations

Magnetic resonance guided radiation therapy (MRgRT) combines magnetic resonance imaging (MRI) and radiation therapy to enable the visualization of anatomy in real time during treatment. The presence of a magnetic field in MRgRT affects charged particle radiation and detector responses, necessitating changes to traditional reference dosimetry procedures. The American Association of Physicists in Medicine (AAPM) Task Group 351 (TG-351) provides a formalism for reference dosimetry in MRgRT. In this study, the TG 351 formalism is used to perform reference dosimetry for a 6 MV flattening filter-free (FFF) photon beam from a Viewray MRIdian MR-Linac radiation therapy system. Beam quality determination, …

De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis

Theses and Dissertations

De novo proteins are structurally distinct from proteins found in nature and thus capable of having their amino acid sequence modified to accomplish tasks such as increasing protein-nanoparticle binding without unfolding or decomposing. Zinc Oxide nanoparticles are functionally distinct from their bulk counterparts and are widely used as semiconductors in a variety of fields such as medicine and agriculture. With demand for these nanoparticles increasing, environmentally sustainable methods of Zinc Oxide nanoparticle synthesis are being investigated as an eco-friendly alternative to currently utilized but environmentally hazardous chemical and physical techniques. This research investigates the binding characteristics between Zinc Oxide nanoparticles …

Conceptual Concerns Regarding The Content Validity Of The Construct Of Gender Dysphoria In The Diagnostic And Statistical Manual Of Mental Disorders, Fifth Edition, Text Revision, Waverley Vesely

Theses and Dissertations

The diagnostic classification of gender dysphoria in the DSM-5-TR elicits a number of clinical, political, and philosophical concerns, ranging from those that are diagnostic and taxonomical in nature to those that fall within the domains of ontology, phenomenology, and hermeneutics. Part of the reason for the complexity of studying the diagnostic and nosological validity of gender dysphoria as an extant diagnostic classification is that, unlike many disorders, gender dysphoria is inextricably tethered to identity. While the recent change from gender identity disorder to gender dysphoria has nominally removed the status of disorder, in practice, both clinicians and the general population …

The Relationship Between Symptom Catastrophizing And Sociocultural Factors Among Adults With Persistent Sympathetic Activation Syndromes, Whitney M. Redemer

Theses and Dissertations

Persistent Sympathetic Activation (PSA) has emerged as a potential unifying mechanism underlying a range of complex chronic health conditions yet remains poorly characterized within biomedical and psychosocial research. Limited research has delineated how PSA manifests across diverse populations or how diagnostic and sociocultural factors shape lived experiences of this phenomenon; thus, the objective of the present study was to examine whether diagnostic certainty – operationalized as provider-confirmed versus self-suspected PSA-related diagnoses – is associated with symptom catastrophizing, and whether this relationship varies as a function of sociocultural factors. Drawing on data from a larger study aimed at characterizing the lived …

Foreign-National Families, Education, And Parenting: Unpacking The Influence Of Cultural Transitions On Child-Rearing And Expectations, Yuqi Zhang

Theses and Dissertations

This qualitative study examines how highly skilled foreign-national parents navigate parenting and educational decision-making within the context of cultural transition in the United States. While existing research on foreign-national parenting has largely focused on socioeconomically disadvantaged populations, less is known about families who possess substantial educational and professional capital. Despite these advantages, these parents encounter unique challenges related to institutional navigation, identity negotiation, and social constraints. Guided by Bronfenbrenner’s bioecological theory, Coleman’s social capital theory, Berry’s acculturation framework, and Yosso’s community cultural wealth model, this study explores how cultural background and migration experiences shape highly skilled foreign-national families’ parenting beliefs …

Evaluating Novel Targeted Combination Therapies For Gastrointestinal Cancers, Joseph A. Goode

Graduate Studies Theses and Dissertations 2026

Gastrointestinal (GI) cancers remain among the leading causes of cancer-related mortality worldwide, with therapeutic resistance continuing to limit the effectiveness of current treatments. Three complementary studies were conducted to identify therapeutic vulnerabilities and evaluate novel combination strategies in pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer (CRC).  First, dual inhibition of fibroblast growth factor receptor 4 (FGFR4) and phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling was investigated in PDAC models. A combination of targeted drug treatments reduced viability, clonogenic survival, migration, and suppressed signaling pathways involved in translational control. This supported a functional interaction between FGFR4 and PI3K-mTOR co-activation in …

Spectrum Of Neurodevelopmental Disorders In Children Attending A Developmental Clinic In Dar Es Salaam, Tanzania, Aleya Zulfikar Remtulla, Sumayyah Nasiruddin Saudin, Orujul Hassan, Mariam Noorani

Paediatrics and Child Health, East Africa

Background: Neurodevelopmental disorders (NDDs) in children present significant challenges for healthcare systems globally. In Tanzania, children with NDDs and their families face significant challenges due to late diagnosis, lack of standardized screening tools, widespread stigma and cultural beliefs that deter health-seeking behaviours. Awareness about NDDs is low, and financial constraints further complicate access to necessary medical interventions. The country suffers from a severe shortage of specialized healthcare providers, and general healthcare providers often lack adequate training. Additionally, limited specialized facilities, high treatment costs and insufficient healthcare policies dedicated to NDDs make it difficult to manage these conditions effectively. Understanding the …

(Reverse) Piercing The Trust Veil, Eric Kades

Faculty Publications

Emergent doctrine deems trusts legal entities distinct from their trustees and beneficiaries. Venerable doctrine empowers creditors to "pierce the veil" separating entities' and their owners' property to avoid inequitable treatment. This article weaves together the new and old to craft a legal roadmap for reversing the ongoing race to the bottom among the states authorizing indefensible self-settled asset protection trusts (SSAPTs) designed solely for the purpose of swindling creditors. As a matter of both policy and doctrine, piercing (more precisely, reverse piercing) an entity's veil is ideally suited to empower the creditor of a SSAPT beneficiary to get paid from …

Visual Cues Of Human-Likeness, Not Salience, Impact Trust-Related Human-Computer Interaction, Jordan Schotz

Graduate Studies Theses and Dissertations 2026

As interactions with digital agents become increasingly integrated into daily life, understanding how visual representations influence social decision-making is critical. Previous research in human-computer interaction has frequently confounded the psychological effects of an agent's perceived human-likeness with the underlying visual salience of the stimuli. To address these persistent gaps, the present study systematically isolated the effects of human-likeness and visual cue trustworthiness on trust behavior while controlling for objective image properties. The present study expanded on and normed the Virtual Avatar Facial Stimuli Set (VAFSS), a comprehensive database comprising hundreds of identity-matched photographs and computer-generated avatars varying across a spectrum …

Unmasking Pentastomes: Generating Genomic Resources For Enigmatic Parasites, Stephanie Lyn Villella

Graduate Studies Theses and Dissertations 2026

The introduction of invasive species can disrupt ecosystems not only through competition and predation but also by introducing novel pathogens to naïve host populations. In the southeastern United States, the invasive Burmese python (Python bivittatus) has been implicated in the introduction of the pentastome parasite Raillietiella orientalis, which has been associated with increased parasite burdens and mortality in native snakes. Despite their ecological significance and ancient evolutionary history, pentastomes remain poorly represented in genomic databases, limiting efforts to understand their evolutionary origins, host–parasite interactions, and mechanisms underlying parasite emergence. This study addresses these gaps by generating the …

Site Use And Demographic Changes In A Northwest Atlantic Sea Turtle Foraging Ground, Ryan C. Welsh

Graduate Studies Theses and Dissertations 2026

and site fidelity, making mortality difficult to distinguish from redistribution. We developed a behaviorally explicit framework to separate true mortality from changes in availability caused by movement and redistribution. We evaluated this problem for juvenile green turtles (Chelonia mydas) and loggerhead turtles (Caretta caretta) captured at the St. Lucie Nuclear Power Plant intake canal on Florida’s Atlantic coast using a multi-decade capture–mark–recapture record spanning 1977 - 2023. Hidden Markov Models classified individuals into latent habitat-use strategies (Nomadic, Resident, and Transient) based on capture timing and body size. Across both species, these strategies captured consistent differences in site fidelity and recapture …

Ecological And Evolutionary Responses To Environmental Change In Two Large North American Mammals, George Zaragoza

Graduate Studies Theses and Dissertations 2026

Climate change and urbanization are resulting in rapid shifts in ecosystems. The effects of these changes are complex, and understanding how species respond is critical for predicting their impacts on genetic diversity and evolution, as well as changes in habitat suitability. Species can respond to these changes in two major ways: through behavioral or genetic adaptation, or by moving to more suitable habitat as conditions change. Adaptive genetic change, in particular, can support behavioral and physiological responses that enable species to persist in novel or changing environments, and understanding these changes can help predict how species will respond to anthropogenic …

Machine Learning-Based Intrusion Detection System For Iot Networks Using The Rt-Iot 2022 Dataset, Bukunmi Ebenezer Afolabi

Theses, Dissertations and Capstones

The rapid expansion of the Internet of Things (IoT) has transformed modern computing by enabling seamless connectivity among heterogeneous devices across diverse application domains. However, this increased interconnectivity has significantly enlarged the attack surface of IoT networks, exposing them to a wide range of sophisticated cyber threats. Conventional security mechanisms often lack the capability to detect emerging attacks in real time, thereby necessitating the development of intelligent Intrusion Detection Systems (IDS) capable of accurately identifying malicious network activities. This study developed and evaluated a machine learning-based intrusion detection framework for multiclass IoT attack detection using the RT-IoT2022 dataset. The dataset …